I've recently hooked up an Ultra driven by a Fidek 4002 amp. I'm using 1 channel of the stereo amp - 400w. The Sub is corner placed in a large family room that opens to a kitchen, hallway, etc. I'm very happy with the sub...a definite improvement over my prior HSU-VTF 2. The problem I'm having is that I can't get the sub to reference level when calibrating. I have the amp volume turned to max & the sub level on my Denon 3802 set to a max of +12. While my speakers are calibrated to 75db, I can only get the sub up to 70db. (I'm still getting huge output...but would prefer to set the sub level on the receiver at 0 or below) Should I try the amp bridged at 800w...or is that too much for the sub?